Enterovirus Infections

What are enteroviruses?  Enteroviruses are small viruses that are made of ribonucleic acid (RNA) and protein. This group or family of viruses includes the polioviruses, coxsackieviruses, and echoviruses. In addition to the three different poliovirus strains, there are about 100 non-polio enteroviruses that can cause disease in humans: Coxsackie A viruses,  Coxsackie B viruses, echoviruses, and other enteroviruses that are designated by numbers.  All three types of polioviruses have been virtually eliminated from the Western Hemisphere by the widespread use of vaccines.  Only the non-polio enteroviruses are known to cause disease in the US.  Non-polio enteroviruses are second only to the "common cold" viruses (the rhinoviruses), as the most common viral infectious agents in humans.  It is interesting that rhinoviruses and enteroviruses are very similar.  Enterovirus infections are among the most common reasons a pediatric patient will visit a pediatrician.  The enteroviruses cause an estimated 10-15 million or more symptomatic infections a year in the United States.

What illnesses or symptoms do these viruses cause?

Enteroviruses cause many different symptoms in infected individuals. Most enterovirus infections are not serious at all and resolve on their own without treatment.  Typically, the younger the infected person, the more severe the disease.  Some very young infants infected with an enterovirus may have the appearance of sepsis (a severe bacterial infection of the blood) with high fever and lethargy, requiring tests to investigate what is causing the illness.  Newborns who become infected with an enterovirus may rarely develop an overwhelming infection of many organs, including liver and heart, and die from the infection.  Thankfully this is very rare.  Because most adults have quite a bit of immunity to enteroviral infections, breastfeeding is a very good way to prevent this possibility by passing on maternal immunity to the child through breast milk.

Thankfully, older children who become ill with enterovirus, usually develop much milder symptoms.  This may include upper respiratory symptoms much like a "cold" with a runny nose, sore throat and cough.  Headache is common with an enterovirus infection.  Other children may develop a flu-like illness with fever and muscle aches.  Many enteroviral infections may cause a rash. Typically the rash is characterized by many very small, flat red dots on the skin of the chest and back with individual lesions having the size of a pin head (1/8th of an inch).  Another, prominent feature of enterovirus infection is the development of vomiting and diarrhea sometimes associated with abdominal pain.  Mouth ulcers are also possible.  An individual child may have one or all of the above mentioned symptoms with any particular infection.

It is a very common scenario for a child with enterovirus infection to develop fever and vomit a few times on the first day of the illness. Then shortly later develop mild abdominal pain and mild diarrhea followed by symptoms of runny nose, cough and a mild sore throat.  As the illness goes away by day 5 to 7, a fleeting rash as described above, lasts for 1 to 3 days and then fades.  The child completely recovers. 

Another common peculiar enterovirus infection syndrome is known as hand, foot and mouth disease, in which the child develops ulcers and blisters on the hands, feet and in the mouth.  Sometimes a child with hand foot and mouth disease may also have blisters on the buttocks.    The most common cause of hand, foot and mouth disease is coxsackievirus A16, although sometimes, the infection is caused by enterovirus 71 or other enteroviruses.   Like other enterovirus infections, this is typically a minor illness that resolves on its own.

Rarely, some persons with enteroviral infections may have aseptic or viral meningitis. Usually, there are no long-term complications from aseptic meningitis.  Eye infections can also occur.  Recovery is the rule.  Very rarely, a person may develop an illness that affects the heart (myocarditis) or the brain (encephalitis) or even have an infection that causes paralysis. Thankfully severe infections like this are very very rare.  Enterovirus infections are suspected to play a role in the development of juvenile-onset diabetes mellitus (sugar diabetes). Most adults who are infected with an enterovirus actually have no disease at all.

How does someone become infected with one of these viruses?

Enteroviruses can be found in the respiratory secretions (e.g., saliva, sputum, or nasal mucus) and stool of an infected person. Other persons may become infected by direct contact with secretions from an infected person or by contact with contaminated surfaces or objects, such as a drinking glass or telephone. Parents, teachers, and child care center workers may also become infected by contamination of the hands with stool from an infected infant or toddler during diaper changes.

On average, enteroviruses cause about four infections per child per year during the first several years of a child's life.  Once a child has had an infection with a specific enterovirus, the child is typically immune to that particular virus for life.  Doing the math, 61 possible infections at 4 infections per year means that a typical child is immune to most enteroviruses by the time they are an adult.  So, these are truly "pediatric viruses" primarily affecting children.  This is why a child may become ill with a certain enterovirus and the parent usually will not become ill with that virus.  However, everyone is potentially at risk. Infants, children, and adolescents are more likely to be susceptible to infection and illness from these viruses, but adults can also become infected and ill if they do not have immunity to a specific enterovirus.  In the United States, infections caused by the enteroviruses are most likely to occur during the summer and fall.   No vaccine is currently available for prevention of infection with the non-polio enteroviruses.

Treatment:

  1. The treatment of an enterovirus infection is supportive and determined by the symptoms present.  Because it is a virus, there is no definitive treatment to stop this infection.
  2. Cold symptoms are treated according to our "common cold" guidelines.
  3. Painful mouth ulcers of Hand, Foot and Mouth disease are treated with an equal mixture of Benadryl and Maalox liquid.  The dose is one teaspoon of Benadryl and one teaspoon of Maalox mixed together per 22 pounds.  The child should swish this mixture around in her mouth to help ease the discomfort.  You may repeat this treatment every four hours. 
  4. Vomiting and diarrhea are treated according to "vomiting and diarrhea" guidelines of this website.  Give plenty of fluids to prevent dehydration.  Sometimes promethazine or Zofran can be prescribed to control nausea and vomiting at an office visit if the vomiting is bothersome.
  5. Fever is treated according to our "fever" guidelines on this website.  We generally discourage the treatment of fever with enterovirus infections unless your child has a history of seizures, so that your body can fight off this infection more effectively.
  6. The rash of enterovirus is treated with Benadryl.  See our dosing guidelines for Benadryl.
  7. More serious symptoms such as meningitis or encephalitis (severe headache and stiff neck), and myocarditis (chest pain and extreme fatigue) require the immediate attention of one of our physicians.  These complications are very rare.
  8. Newborns with enterovirus infections require our immediate attention.